To fulfill the demanding for information exchanging and instant messaging, mobile communication devices (such as feature phones, smart phones, tablet computers, etc.) become necessary tools for social communication. With the development of mobile telecom network, the mobile communication device connected to the mobile telecom network can be utilized for transmitting/receiving messages, answering/making phone calls, receiving emails or other Internet information and other equivalent applications.
Subscriber identity module (SIM) cards inserted in the mobile communication device are the main reason that the devices are capable to access the mobile telecom network and be recognized as specific user identities. Each SIM card records a specific identification code, which is used to verify the identity of each user on the mobile device.
Every morning, people in the modern society usually leave their home for work in a hurry, and sometimes they may forget to bring their mobile communication devices. If they can not manage to go back and fetch the mobile communication device (e.g., when users go aboard during a long business trip), the users may miss many important phone calls or messages, and even encounter some business losses. Even though the users could borrow or buy another mobile communication device for temporary usage, the users can not fetch the SIM cards within their original mobile communication devices. In other words, the users can not transmit/receive information with their original phone numbers (or as their original identities). In this case, the users are required to set up a call-forwarding from the original numbers to temporary numbers, or notify the relevant persons about the temporary numbers. It is inconvenient to the users when their original SIM cards are inaccessible.